Magnetic contactor



H. L. VAN VALKENBURG.

MAGNETIC CONTACTOR.

APPLICATION FILED JULY 25.1918.

Patented June 1, 1920.

2 SHEETS-SHEET I.

H. L. VAN VALKENBURG.

MAGNETIC CONTACTOR.

APPLICATION man my 25. 1918.

Patented June 1, 1920.

Z SHEETS-SHEET 2 to reduce the length UNITED STATES PATENT OFFICE.

HERMON L. VAN

VALKENBURG, OF MILWAUKEE, WISCONSIN, ASSIGNOB TO PORATION OF WISCONSIN.

MAGNETIC CONTACTOB.

Specification of Letters Patent.

Patented June 1, 1920.

Application filed July 25, 1918. Serial No. 246,636.

'1 '0 all whom it may concern:

Be it known that I, HERMON L. VAN VALKENBURG a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented a certain new and useful Improvement in Magnetic Contactors, of which the following is a specification.

My invention relates to electromagnetic contactoi's, more particularly for use on alternating current. One of the principal objects of the invention is to provide a contactor which will not chatter, even though it may have some inaccuracies due to manufacture in quantity. The tendency to chatter is greatly reduced by providing a comparatively large surface over which the armature of the electromagnet ma contact the pole piece, and so designing t e apparatus that said parts will engage over the entire available contact area. It is my purpose to provide means whereby contact may always occur over the entire surface even though be manufactured in the device may quantity and hence not be formed with that has heretoextreme care and nicety which fore been necessary to reduce the vibration in this class of apparatus. With this in view, I make the connection between the armature lever and the shaft somewhat loose and hence the armature is slightly independent of the shaft and may adjust itself to the stationary magnet pole. Another object of the. invention is to provide a construction by which the parts may be brought closely together without weakening them, thus making the device more compact and reducing the amount of space and material required for it. In carrying out this feature of the invention I have made it possible of the main sha Moreover, by reducing the length of the shaft its relative rigidity and stiffness is increased. Still another object is to provide a construction lending itself to the easy removal of the magnet coil for replacement and repairs.

I accomplish my objects by mechanism illustrated in the accompanying drawings in which- Figure 1 is a apparatus.

front view of the complete Fig. 2 is a sectional elevation on the line 2-2 Fig. 1.

Fig. 3 is a sectional elevation on the line 3-3 Fig. 1.

Fig. 4 is a sectional elevation on the line 4--4 Fig. 2.

Fig. 5 is a perspective view of the armature pole piece and associated parts.

Similar numerals refer to similar parts throughout the several views.

Ordinarily the apparatus is mounted upon a panel 1 of marble, slate or other material. In the design selected to illustrate the invention the main shaft 2 is journaled in brackets 3, 3 suitably fastened to the front 0f the panel. Except at the reduced. cylindrical ends 6 where theshaft is journaled in the brackets, it is square and carries the SW1tCh arms 8 which are-here shownjto be three in number. As the switchesfithemselves are not particularly. concerned with the invention it will be sufficient to say that in the form shown the shaft is inclosed in an insulating sleeve 9 and the switch arms are held to it by clips 10. A spring contact terminal 12 1s carried at the free-end of each switch arm in position to enga a cooperatng stationary contact terminaI hB, fastened in any suitable manner to the panel.

Now referring more particularly to the electromagnetic parts of thisjdevice, a pole piece 20 is rigidly fastened to. the panel and enc rcled b a coil 21 by which it is magnet zed. his coil is self contained in the sensethat it can be removednsa'wholeby slipping it forward off the end of its core or pple piece. In the form illustrated the 'pole piece forms part of a U-shaped frame which, when the armature is in closed; position, forms with it a closed magnetic circuit. By preference the pole piece and fr'ameare laminated. The armature consists of a plate 25 arran ed in the plane of the magnet frame an having on each side of it a number of laminations 26. These are preferably held in place by suitable outer plates 27. Thus the armature is built up. of a center plate having a preferably equal number of laminations on each side of it. The armature is built up to a considerable width, as is also the pole piece, thus giving a relatively large area over which the two may contact each other. In the devices heretofore made, it is frequently found that the armature does not seat squarely against the pole piece. I have avoided the difiiculty by employing a comparatively thin plate 25 and forming a square hole 30 in it slightly larger than the shaft. The result is that the armature rotates the shaft far enough to obtain good contact when the arms are closed and yet there is sufficient lost motion to enable the armature to seat squarely upon the pole piece. The thinness of the plate 25-permits the parts to be appreciably out of alinement without throwing the armature'out of alinemnt with the pole piece. In other words there is some room to come and go angularly, that is, in a plane perpemlirular to the shaft and also laterally in both directions. If the armature had a long hearing on the shaft, :1 comparatively small mis-location of the shaft might readily permit the armature to contact the pole piece-only at one corner or along one edge or side, whereas with my construction where the length of bearing along the shaft is greatly reduced there is room for automatic adjustment ofthe 'armature in every direction without however, defeating its furictio'n of closing-and opening the switch.

An arin 36 which is preferably integral with plate 25 extends back under the magnet frame to serve as-a stop for preventingthe armature hem swinging forward when the pole piece is denergized. The arm and plate are positioned laterally upon the shaft by means of'clips or keepers 33 located a slight distance away from the :plate on either side of it. These clips are fastened in place'b y screws 35 or other appropriate means. One of the advantages in having the arm thi n is that it facilitates the removal of 'the coil 21 from the pole piece. Being thin, the plate can be shifted laterally on the shaft a greater distance before strikin the sleeve Sthan if the plate were as thicfi as the armature. In 'my device,.by reason of the thinness of the plate, it and its armatiire can be moved s'idewise far enough to permit the coil to be drawn off of the pole piece without strikingthearmature.

The operation of the device will be apparent. Whenthepole piece becomes energlzed and attracts the armature the latter will'rotate'the' shaft and move the switch arms to open or closed position as the case may be, the present case showing the switch'arms closing when the armature moves up to the pole piece. The novel mechanical connection between the armature and the shaft-permits thearmature'to adjust itself and seat accurately upon the "pole p'iece even though the parts may be appreciably out of position 'ortheparts may exhibit noticeable 1naccuracies of manufacture.

Having thus described my inve1ition,wlmt I claim as new and desire to secure by Letters Patent, is

1. An alternating current magnetic contactor havin a main operating shaft one portion of w ich is polygonal in cross section, a pole piece, and an armature fitting somewhat loosely over the polygonal portion of said shaft whereby the armature is capable of operating the shaft but is, within reasonable limits, independent of said shaft, thus enabling it to adjust itself to the pole piece.

2. An alternating current inagnetic'contactor having a main operating shaft, one portion of which is polygonal in cross section, a pole piec'e, and an armature comprising a plate and permeable material secured to said plate to form an armature, the width of the plate being less than the total width of the armature and the plate loosely fitting the polygohal -portion of the shaft.

3. An alternating current magnetic contactor, having a main operating shaft, a comparatively thin plate engaging said shaft for. rotating it, an electromagnetic pole piece, and an armature cotiperating therewith,,; said armature bein mounted upon said plate and being o'f a wldthgreater than the thickness .of the plate.

4,-A 'm etic contactor having a main operating s aft, a pole iece, a coil for magnetizing it, an armature cotiperating [with the polewpiece said armature emg connected to the shaft -fpr rotatinglt andbeingfslidable lorrgitndinally of th shaft whereby it may be'shifted to one side of the pole piece to-permit thei'removal o f tlie'coil.

5. A magnetic contactor having a poly-gonal operating shaft, a pole piece, a magnet coil surrounding said. pole piece, in armature cooperating with the pole piece, said armature fittin over said loosely enoughto be sli ablelongitudinally whereb a and the armature may be S ifted 1aerally'to permit the coil to be withdrawn from the pole pieee withoutthe'necessity of removing the armature fibm the shaft.

6. A magnetic contactor having a main operating shaft, a pole. piece, aboil'formagnetizing it, a lfelat vely thin plate carrying an armature adapted to coiipe'lfate with the pole-piece for actuating said plate and rotatingthe shaft, a stationary stop in line with said-plate, said platehavin'g an arm extending from it and adapted "to engage said stop for limiting the moveme'iitf of'the armature away from t e pole'piece, said plate being slidable toenable to be shifted to one side to permit the coilto be withdrawn from the pole piece.

7. An alternating current magnetic contactor having a main operating shaft, an insulating sleeve thereon, switch arms fastened to the shaft over the sleeve, the sleeve extending along the shaft beyond the outermost switch arm, an electromagnet located at the side of the switch arms and consisting of a pole piece and a removable coil surrounding it, and an armature cooperating with the pole piece, said armature being of considerable width, lengthwise oil the shaft, and being secured to the shaft by means of: a plate slidable lengthwise of the shaft, said plate being thin compared to the width of: the armature, whereby the armature may be shifted close to the nearest switch arm, for removal of the coil, without interference between the sleeve and the plate.

8. A magnetic contactor having a main operating shaft having a squared portion, a stationary pole piece, an armature, the pole piece and armature having considerable area over which they may make contact, and a lever supporting said armature, said lever being adapted to engage said shaft for ro tating it, and said lever being loosely connected to said shaft whereby the armature may seat s uarely against the pole piece regardless o ordinary inaccuracies of alinement of the shaft.

9. A ma netic contactor having a main operating s aft, a pole piece, an armature cooperating with the pole piece, a relatively thin plate for connecting the armature with the shaft for rotatin it, said plate being slidablc lengthwise oi the shaft, and a removable clip fastened to the shaft for normally holding the plate in position.

10. An alternating current Ina netic contactor having switch arms, a sha t carrying said arms for operating them, an electromagnetic pole piece, an armature cooperating therewith, a plate carrying said armature and engaging the shaft for rotating it, said plate being shiflable along the shaft and normally held in position laterally by clips remorably attached to the shaft.

In witness whereof, I have hereunto subscril'icd my name.

HERMON L. VAN VALKENBURG. 

